SOME EAST AFRICAN PIGS 
41 
It is said to extend to the boundaries of the Semliki forest, but 
in forest regions it is usually replaced by the Bush pigs and 
River hogs. Its most noticeable features are the nearly naked 
skin with a crest of long hair on the withers and back, the large 
development of the canine teeth, the deciduous character of 
the other teeth excepting the last molar and lower incisors, and 
the development of large tubercles or warts on the skin of the 
face. The object of these last-mentioned tubercles seems to be 
protection against the tusks of rival pigs, as they are infinitely 
more developed in the boar than in the sow. The warts are 
six in number, three on each side of the face. The first pair 
are conical and situated near the lateral base of the nasal 
bones, a projection of bone (on the zygoma) supporting them. 
The second pair are below the orbit, also on its bone above the 
insertion of the lower jaw, evidently designed to protect the 
eye. The other pair, which are elongated horizontally, are on the 
skin of the lower jaw. 
These in the sow and young boar usually carry a tuft of 
whitish hair turned upwards like a whisker; this whitish hair 
also occurs in the Giant pig, especially in sows. 
With reference to the tusks the upper pair are used for 
excavation, enlarging the burrow, and to some extent as a 
shield ; while the lower are used for offence. The upper tusks, 
which are of a softer material than the lower, being composed 
of dentine (while the lower are covered with enamel), also serve 
as a hone to keep the lower tusks sharp. When delivering a 
slash the pig sets its lower jaw much to one side, the mouth 
being open, the characteristic right and left ‘ dig ’ of the pig 
being well known. 
With regard to the deciduous character of the adult teeth 
it has been observed that, while the young Warthog may have a 
nearly full complement of teeth — viz. upper jaw two to four in- 
cisors, two canines, seven or eight premolars, and four molars ; 
in the lower jaw, six incisors, two canines, four premolars, 
four molars ; or, in a dental formula, - — - incisors, 
3—3 
j j 4 g 2 2 
- — - canines, premolar, molar — in the adult this 
1—1 2-2 F 2—2 
is changed. 
